Screw-threading die.



A No. 777,442. PATENTED DEC. 13, 1904.

- A. J. SMART.

SCREW THREADING DIE.

APPLIUATION FILED APR.13.1904.

NU MODEL.

@N'ormu S- No. 777.442. Patented December 13, 1904.

UNITE STATES PATENT OEEIcE.

ALBERT J. SMART, OF GREENFIELD, lVIASSACHUSETlS, ASSIGNOR TO WILEY & RUSSELL MANUFACTURING COMPANY, OF GREENFIELD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

SCREW-THREADING DIE.

SPECIFICATION forming part of Letters Patent N 0. 777,442, dated December 13, 190%. Application filed April 13,1904. Serial No. 203,002. (No model.)

T 11/71/01 y III sent the two halves of a divided die formed,

Be it known that I, ALBERT J. SMART, a citipreferably, of hardened steel, being provided, O

Zen of the United States, residing at Greenas usual, on their inner faces with threads 0,

field, in the county of Franklin and State of forming when put together a female screw 5 Massachusetts, have invented certain new and for cutting threads. The size of this female useful Improvements in Screw Threading screw is adjustable by the means hereinafter Dies; andIdo hereby declare the following to described, which consist, essentially, of a 55 be a full, clear, and exact description of the hinged connection for holding the halves a, and

invention, such as will enable others skilled in 7) together and located substantially entirely to the art to which it appertains to make and use within the material forming the die in combithe same. nation with an arrangement of cones, also sub- This invention relates to screw-threading stantially entirely within the material form- 60 dies, more particularly to what are known as ing the die adapted to separate the halves a divided dies, which allow of adjustment to and b and swing them either apart or together compensate for Wear or to cut screws of difon the hinged connection.

ferent depths and sizes by means of a single As shown more particularly by Figs. at and die and also render repairing and sharpening 5, the hinged connection is preferably formed 5 easier; and the objects of the present invenby providing recesses (Z on both the upper-and tion are to construct a more compact, strong, lower sides of lugs a, left upon the surface of and solid divided die forperforming the funcone pair of meeting ends of the two halves.

tions above described and to obviate many of Between these lugs is interposed a doublethe objections which have heretofore been headed screw-shankf, having preferably one 7 found to exist in dies of this class. head in the form of a nut and one or both of Further objects of the invention will herosaid heads being cup-shaped. In the drawinafter appear; and to these ends the same 0011- iugs both heads are shown cup-shaped, so as sists of ascrew-threading die for carrying out to lit in the double pair of recesses also there the above objects embodying the features of shown. The cup-shaped portion of head r 75 construction,combination of elements, and arfits snugly in the pair of recesses (Z on one rangement of parts substantially as hereinside of the lugs and the cup-shaped portion after fully described and claimed in this of nut la, which nut is preferably of similar specification and shown in the accompanying proportions to head y, fits snugly in the pair drawings. of recesses (Z on the opposite side of lugs e. 80

While the essential and characteristic fea- It will be readily seen that such a constructures of the invention are susceptible of modition forms an exceedingly compact and effification, still the preferred embodiment therecient hinge-joint, which may be made tight or of is illustrated by the figures of the drawloose at will and always accessible. The adings, in which justing means (shownmore particularly by 8 5 Figure 1 is a plan view of the die. Fig. 2 Fig. 3) consist of a screw-shank *5, provided is a sectional view of the die through the aclwith a conically-formed head j and leading 4 justing and connecting means. Fig. 3 is a, into a nut 7 in the form of a conical frustum, sectional view on the line 3 3 of Fig. 2, shovthe whole being interposed between the pair ing the construction of the cone adjustment. of meeting ends of the halves of the die op 9 Fig. 4 is a sectional view on the line t i of posite the hinge connection, the comically- Fig. 2, showing the construction of the hinged formed head 1' and nut Z, fitting snugly into connection; and Fig. 5 is an enlarged detail of recesses 6, formed in said meeting ends and the recesses in the separable parts of the die constructed to receive them. This construcforming a part of the hinged connection. tion also allows access by the workman under Referring to the drawings, a and b repreall conditions.

The advantages of such a construction are manifest, as it forms a die standing complete in itself and entirely does away with the necessity of the guide or collet, which had to be used in former constructions of an adjustable divided die, and under any adjustment the die is held firmly by a pressure evenly distributed upon both the upper and lower edges, keeping them perfectly firm, solid, and true, which is absolutely necessary to cut perfect threads.

To adjust the die, the halves a and Z) are turned upon the hinged connection or pivotal point formed by turning down the screy -head 9 and drawing it and the nut it into engagement with the recesses (Z, formed in the lugs c. To adjust for wear, the taper-headed screw 2' is then withdrawn, forcing the tapered nut outwardly, and the halves a and bare pressed together, while to adjust to cut a screw-thread of larger diameter said screwc' is forced inward, drawing the said nut 1' also inward and forcing the halves a and 5 apart. The adjustment is sure, accurate, and permanent.

It should be understood that this die may be held in any way that a solid die may be held, and therefore may be used with any form of die-holder, either a die-stock for hand working or a chuck for machinework, or adapted to be used in a bit-brace. As the holder does not form a part of this present invention, it is not deemed necessary to illustrate the die in combination therewith.

Obviously some features of this invention may be used without others, and the invention may be embodied in widely varying forms.

Therefore, without limiting the invention to the construction shown and described nor enumerating equivalents, I claim and desire to obtain by Letters Patent the following:

1. In a divided die for cutting screw-threads connecting means comprising a double-headed shank, one of said heads being cup-shaped, and means on the die parts with which said head is adapted to engage, substantially as de scribed.

2. In a divided die for cutting screw-threads, connecting means comprising a shank provided with an integral and a movable head, one of said heads being cup-shaped, and means on the die parts with which the cup-shaped head is adapted to engage, substantially as described.

3. In a divided die for cutting screw-threads, ahinge between the die parts consisting of a cup-headed screw having a cup-shaped nut threaded thereon, and recessed lugs on the die parts with which said members are adapted to engage, substantially as described.

4. In a divided die for cutting screw-threads, a hinged connection comprising two cupshaped members, means on said die parts with which said members are adapted to engage, and connecting means adapted to hold said members in place, substantially as described.

5. In a divided die for cutting screw-threads, a hinged connection comprising a recessed lug on each of said die parts, two cup-shaped members constructed to engage with said recesses, and connecting means adapted to hold said cup-shaped members in place, substantially as described.

6. In a divided die for cutting screw-threads, a hinged connection comprising a lug on each of said parts provided with recesses on each side thereof, a screw-shank between said lugs having a cup-shaped head constructed to engage with the recesses on one side and a cupshaped nut on said screw-shank constructed to engage with the recesses on the other side, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

ALBERT J. SMART.

IVitnesses:

WM. A. DUNFERT, FRANCIS NIMs THoMrsoN. 

